1. Field of Endeavor
The present disclosure relates to a transmission and a traction motor module using the same.
2. Background
The pedal cycle may be, for example, a conventional pedal cycle in which drive is only ever provided by a cyclist applying force to the pedals thereof, such cycles sometimes being referred to as “push bikes”.
Recently, the pedal cycle has evolved to, for example, a pedelec, an EAPC (electrically-assisted pedal cycle) an electric bicycle or an e-bike. The electrically-assisted pedal cycle (EAPC) or an e-bike is operated by a motor in such a manner that electrical power is used to assist the efforts of a cyclist pedaling the cycle.
Several methods of arranging a motor have been attempted and a recent method is to embed a motor and a transmission inside a hub forming a front wheel or a rear wheel. The hub is integrally formed with the motor and the transmission therein. An example of this type of e-bike motor is disclosed by the Korean Patent Registration No.: 10-1055022 filed on Aug. 5, 2011.
The hub includes a housing and a stationary shaft. The motor is arranged inside the hub housing, and the stationary shaft is fixed to a front wheel or a rear wheel of a frame of an e-bike or an e-scooter. As a result, the hub housing is rotated relative to the stationary shaft to rotate a wheel of the bike coupled to the hub housing.
The motor is housed inside the hub housing to rotate a rotation shaft by means of electromagnetic interaction. The motor housing of the motor is fixed relative to the hub housing, and a rotation shaft rotatably arranged in the center of the motor housing transmits a turning effect to a sun gear integrally formed with a distal end thereof, whereby a power is supplied to a transmission including the sun gear.
The transmission is provided with a plurality of planetary gears meshed with the sun gear and a ring gear arranged at a margin of the transmission to mesh with the planetary gears, whereby the transmission receives the turning effect of the rotation shaft in a reduced speed.
Meanwhile, the other surface of an inner circumferential surface meshed with planetary gears of the ring gear is provided with a clutch member for enablement of gear transmission, where the clutch member is integrally formed at a surface opposite to the gear member meshed with the plurality of planetary gears for double clutch transmission through forward and backward rotations.
The ring gear integrally formed with the gear member and the clutch member is manufactured through cold forging or hot forging process, such that problems arise in that the gear member is manufactured as a spur gear to create noise and push up the manufacturing cost, and no other engineering processes can produce the ring member.